It has been proposed for various reasons to form at least one piston of a axial piston machine as a stepped piston, whereby two cylinder spaces are formed. The cylinder spaces can be connected to two throughput lines separated from one another in order, e.g. to divide the throughput volume, cf. U.S. Pat. No. 3,126,835, or else one of the two cylinder spaces can serve merely to press the piston or pistons against an inclined driving surface, or to press a cylinder barrel against the control surface, cf. DE-PS No. 707 462.
In order to improve the sliding bearing between the piston and the driving surface it is known to provide between the sliding surfaces a fluid cushion such as a pressure pocket supplied from the respective cylinder space, which reduces the pressure per unit area and therefore the friction and the wear of the sliding surface both on the piston side and on the driving surface of the sliding bearing, i.e. it brings about a certain reduction in the loading of the sliding bearing.